Highway plans aim to keep habitat — and wildlife
— in one place

Artist's rendition of a wildlife over-crossing planned for
I-90 east of Seattle. Similar over-crossings in Banff, Canada,
resulted in an 80 percent drop in wildlife mortality near the
road

Washington Department of Transportation

In the Cascade Range, the question isn’t why
animals cross the road, but how they can do so without becoming
salamander road-cakes or elk a la SUV.

The answer, say
Washington state transportation officials and biologists, lies
under and over a humming mountain highway.

In June, the
state’s Department of Transportation released plans for
widening a 15-mile section of I-90 east of Seattle, smack in the
middle of a major wildlife thoroughfare. To reduce auto-animal
collisions, the plans include several types of wildlife passages
modeled after successful critter crossings in Arizona and Florida
and on Banff’s Trans-Canada Highway (HCN, 2/7/05: Caught in
the Headlights).

The road improvement project, slated to
begin in 2011, will be a "showpiece" of ecological highway
building, says Kim Vaughn, a transportation department design
supervisor. Work could include improving culverts to aid smaller
mammals and reptiles, creating hydrologic connections for fish and
amphibians, and building the country’s first wildlife
over-crossing, a wide bridge carpeted with native soil and plants.
"We’re targeting a wide range of species, from low-mobility
salamanders to large carnivores," Vaughn says.

Tony
Clevenger, a Montana State biologist, says getting animals across
safely is just the beginning: "Habitat is getting chopped up and
biodiversity is getting scarcer." The real boon of the project, he
says, will be reconnecting the wildlife living on both sides of
I-90 in the Wenatchee National Forest.

So far, the state
has committed $388 million to the highway improvements, most of
which will go to road widening and avalanche-safe tunnels. That
wildlife welfare is also addressed thrills Jen Watkins, a
spokesperson for the I-90 Wildlife Bridges Coalition, which pushed
for including animal crossings in the project: "It’s critical
for us to attack the last barrier for wildlife." The public can
comment on the project through Aug. 5.